How does mica affect concretes ultimate strength?
Q. Recently, a participant in Aggregate Research Industries’ online forum posed the following question on a coarse aggregate problem. The user was concerned with variable aggregate quality and thought that it was impacting concrete compressive strength performance. “I have a coarse google_ad_client = ‘pub-2905054723170537’; // substitute your client_id (pub-number) google_ad_channel = ‘6331884817’; google_ad_output = ‘js’; google_max_num_ads = ‘3’; google_ad_type = ‘text’; google_feedback = ‘on’; aggregate that exhibits limonitic alteration and at times has an abundance of micaceous minerals. Petrographic examination of hardened concrete specimens indicated that clay constituted 5%-10% of the paste. The fine aggregate historically had a sand equivalence of 95 but has dropped to 70.” What impact would these mineralogical variables have in our efforts to produce high-strength concrete? A. Most respondents expressed concern about the use of aggregates with mica and clay particles. One per
